In 1984, the National Highway Traffic Safety Administration (NHTSA) of the U.S. Department of Transportation issued a requirement for frontal crash protection of automobile occupants. This regulation mandated "passive occupant restraints" for all passenger cars by 1992. A more recent regulation requires both driver and passenger side airbags on all passenger cars and light trucks by 1998. In addition, the demand for airbags is accelerating in both Europe and Japan and it is expected that, within a few years, all vehicles produced in these areas (36 million vehicles) and eventually worldwide (50 million vehicles) will be equipped with airbags as standard equipment.
Whereas thousands of lives have been saved by airbags, significant improvements can be made. As discussed in detail in copending patent application Ser. No. 08/040,978 cross-referenced above, and included herein by reference, for a variety of reasons, vehicle occupants can be or get too close to the airbag before it deploys and can be seriously injured or killed upon deployment of the airbag.
Also, a child in a rear facing child seat, which is placed on the right front passenger seat, is in danger of being seriously injured if the passenger airbag deploys. This has now become an industry-wide concern and the US automobile industry is urgently searching for an easy, economical solution, which will prevent the deployment of the passenger side airbag if a rear facing child seat is present. An improvement on the invention disclosed in the above-referenced patent application, as will be disclosed in greater detail below, includes more sophisticated means to identify objects within the passenger compartment and will solve this problem.
Initially, these systems will solve the out-of-position occupant and the rear facing child seat problems related to current airbag systems and prevent unneeded deployments when a seat is unoccupied. Airbags are now under development to protect rear seat occupants in vehicle crashes. A system will therefore be needed to detect the presence of occupants, position, i.e., determine if they are out-of-position, and type, e.g., to identify the presence of a rear facing child seat in the rear seat. Future automobiles can be expected to have eight or more airbags as protection is sought for rear seat occupants and from side impacts. In addition to eliminating the disturbance of unnecessary airbag deployments, the cost of replacing these airbags will be excessive if they all deploy in an accident. The improvements described below minimize this cost by not deploying an airbag for a seat, which is not occupied by a human being. An occupying item of a seat may be a living occupant such as a human being or dog, another living organism such as a plant, or an inanimate object such as a box or bag of groceries.
A device to monitor the vehicle interior and identify its contents is needed to solve these and many other problems. For example, once a Vehicle Interior Identification and Monitoring System (VIMS) for identifying and monitoring the contents of a vehicle is in place, many other products become possible including the following:
Inflators now exist which will adjust the amount of gas flowing to the airbag to account for the size and position of the occupant and for the severity of the accident. The vehicle identification and monitoring system of this invention will control such inflators based on the presence and position of vehicle occupants or of a rear facing child seat.
Side impact airbag systems began appearing on 1995 vehicles. The danger of deployment induced injuries will exist for side impact airbags as they now do for frontal impact airbags. A child with his head against the airbag is such an example. The system of this invention will minimize such injuries.
Future vehicles may be provided with a standard cellular phone as well as the Global Positioning System (GPS), an automobile navigation or location system, is now available on at least one vehicle model. In the event of an accident, the phone may automatically call 911 for emergency assistance and report the exact position of the vehicle. If the vehicle also has a system as described below for monitoring each seat location, the number and perhaps the condition of the occupants could also be reported. In that way, the emergency service (EMS) would know what equipment and how many ambulances to send to the accident site.
Vehicle entertainment system engineers have stated that the quality of the sound in the vehicle could be improved if the number, size and location of occupants and other objects were known. This information can be provided by the vehicle interior identification and monitoring system of this invention.
Similarly to the entertainment system, the heating, ventilation and air conditioning system (HVAC) could be improved if the number, attributes and location of vehicle occupants were known. This can be used to provide a climate control system tailored to each occupant, for example, or the system can be turned off for certain seat locations if there are no occupants present at those locations.
In some cases, the position of a particular part of the occupant is of interest such as: (a) his hand or arm and whether it is in the path of a closing window so that the motion of the window needs to be stopped; (b) the position of the shoulder so that the seat belt anchorage point can be adjusted for the best protection of the occupant; or, (c) the position of the rear of the occupants head so that the headrest can be adjusted to minimize whiplash injuries in rear impacts.
The above applications illustrate the wide range of opportunities, which become available if the identity and location of various objects and occupants, and some of their parts, within the vehicle were known. Once the system is operational, it would be logical for the system to also incorporate the airbag electronic sensor and diagnostics system (SDM) since it needs to interface with SDM anyway and since they could share computer capabilities which will result in a significant cost saving to the auto manufacturer. For the same reasons, it would be logical for VIMS to include the side impact sensor and diagnostic system. As the VIMS improves to where such things as the exact location of the occupants ears and eyes can be determined, even more significant improvements to the entertainment system become possible through the use of noise canceling sound, and the rear view mirror can be automatically adjusted for the driver's eye location. Another example involves the monitoring of the driver's behavior over time which can be used to warn a driver if he or she is falling asleep, or to stop the vehicle if the driver loses the capacity to control it.
Using an advanced VIMS, as explained below, the position of the driver's eyes can be accurately determined and portions of the windshield can be selectively darkened to eliminate the glare from the sun or oncoming vehicle headlights. This system uses electro-chromic glass, a liquid crystal coating on the glass, or other appropriate technology, and detectors to detect the direction of the offending light source. In addition to eliminating the glare, the sun visor can now also be eliminated.
The present invention adds more sophisticated pattern recognition capabilities such as fuzzy logic systems, neural network systems or other pattern recognition computer based algorithms to the occupant position measurement system disclosed in the above referenced copending patent application and greatly extends the areas of application of this technology. An example of such a pattern recognition system using neural networks using sonar is discussed in two papers by Gorman, R. P. and Sejnowski, T. J. "Analysis of Hidden Units in a Layered Network Trained to Classify Sonar Targets", Neural Networks, Vol.1. pp 75-89, 1988, and "Learned Classification of Sonar Targets Using a Massively Parallel Network", IEEE Transactions on Acoustics, Speech, and Signal Processing, Vol. 36, No. 7, July 1988.
"Pattern recognition" as used herein will mean any system which processes a signal that is generated by an object, or is modified by interacting with an object, in order to determine which one of a set of classes that the object belongs to. Such a system might determine only that the object is or is not a member of one specified class, or it might attempt to assign the object to one of a larger set of specified classes, or find that it is not a member of any of the classes in the set. The signals processed are generally electrical signals coming from transducers which are sensitive to either acoustic or electromagnetic radiation and if electromagnetic, they can be either visible light, infrared, ultraviolet or radar.
"To identify" as used herein will mean to determine that the object belongs to a particular set or class containing objects having a similar form. The class may be one containing all rear facing child seats, one containing all human occupants, or all human occupants not sitting in a rear facing child seat depending on the purpose of the system. In the case where a particular person is to be recognized, the set or class will contain only a single element, the person to be recognized.
Some examples follow:
In a passive infrared system, a detector receives infrared radiation from an object in its field of views in this case the vehicle occupant, and determines the temperature of the occupant based on the infrared radiation. The VIMS can then respond to the temperature of the occupant, which can either be a child in a rear facing child seat or a normally seated occupant, to control some other system. This technology could provide input data to a pattern recognition system but it has limitations related to temperature. The sensing of the child could pose a problem if the child is covered with blankets. It also might not be possible to differentiate between a rear facing child seat and a forward facing child seat. In all cases, the technology will fail to detect the occupant if the ambient temperature reaches body temperature as it does in hot climates. Nevertheless, for use in the control of the vehicle climate, for example, a passive infrared system that permits an accurate measurement of each occupant's temperature is useful.
In a laser optical system an infrared laser beam is used to momentarily illuminate an object, occupant or child seat in the manner as described, and illustrated in FIG. 8, of U.S. Pat. No. 5,653,462 cross referenced above. In some cases, a charge-coupled device (a type of TV camera also referred to as a CCD array) or a CMOS device is used to receive the reflected light. The laser can either be used in a scanning mode, or, through the use of a lens, a cone of light can be created which covers a large portion of the object. In each case, a pattern recognition system, as defined above, is used to identify and classify, and can be used to locate, the illuminated object and its constituent parts. This system provides the most information about the object and at a rapid data rate. Its main drawback is cost which is considerably above that of ultrasonic or passive infrared systems. As the cost of lasers comes down in the future, this system will become more competitive. Depending on the implementation of the system, there may be some concern for the safety of the occupant if the laser light can enter the occupant's eyes.
Radar systems have similar properties to the laser system discussed above. The wavelength of a particular radar system can limit the ability of the pattern recognition system to detect object features smaller than a certain size. Once again, however, there is some concern about the health effects of radar on children and other occupants. This concern is expressed in various reports available from the United States Food and Drug Administration Division of Devices.
The ultrasonic system is the least expensive and potentially provides less information than the laser or radar systems due to the delays resulting from the speed of sound and due to the wave length which is considerably longer than the laser systems. The wavelength limits the detail, which can be seen by the system. Additionally, ultrasonic waves are sometimes strongly affected by thermal gradients within the vehicle such as caused by flowing air from the heater or air conditioner or as caused by the sun heating the top of the vehicle causing the upper part of the passenger compartment to have a higher temperature than the lower part. In spite of these limitations, as shown below, ultrasonics can provide sufficient timely information to permit the position and velocity of an occupant to be accurately known and, when used with an appropriate pattern recognition system, it is capable of positively determining the presence of a rear facing child seat. One pattern recognition system which has been used to identify a rear facing child seat uses neural networks and is similar to that described in the above referenced papers by Gorman et al.
A focusing system, such as used on some camera systems, could be used to determine the initial position of an occupant but is too slow to monitor his position during a crash. This is a result of the mechanical motions required to operate the lens focusing system. By itself it cannot determine the presence of a rear facing child seat or of an occupant but when used with a charge-coupled device plus some infrared illumination for night vision, and an appropriate pattern recognition system, this becomes possible.
From the above discussion, it can be seen that the addition of sophisticated pattern recognition means to any of the standard illumination and/or reception technologies for use in a motor vehicle permits the development of a host of new products, systems or capabilities heretofore not available and as described in more detail below.
With respect to prior art related to the detection of child restraining seats, U.S. Pat. No. 5,605,348 (Blackburn et al.) describes method and apparatus for sensing a rearward facing child restraining seat in which a child restraining seat identification tag is secured to the child restraining seat and an antenna coil is energized to transmit an EMF field. The tag is made of an amorphous material that radiates a return EMF signal that is received by the antenna coil. The system determines whether a rear-facing child seat is present based on the presence of the return EMF signal, which is received only if the tag mounted to bottom front of the child seat is within a certain distance from the antenna coil mounted in the back portion of the seat. Drawbacks of the system of Blackburn et al. are that a special tag must be incorporated into the child seat in order to detect the same, the system cannot differentiate between other similarly tagged objects and the system relies on the proper placement of the tag on the child seat. In other words, if the tag were to be improperly placed on the child seat, then the system would not accurately determine the presence and orientation of the same. Also, the system of Blackburn et al. does not generate, e.g., via the antenna coil, a signal based on the contents of the seat which is different depending on the contents of the seat, i.e., the signal for an adult occupant is different from the signal for a forward-facing child seat which is different from the signal for a rear-facing child seat, etc., and analyze the same in order to determine whether the contents of the seat include a child seat in a rear-facing position. Rather, the EMF field generated by the tag is the same signal, and only the power output is varied. Thus, either no signal (no EMF field) will be generated representing the absence of a rear-facing child seat or a signal (an EMF field) will be generated representing the presence of a rear-facing child seat.